Yes i am invested.
I don’t think being a big payers gives you any advantage, What is needed is location & people trust if you have both then a single well maintained lab near by a well known physician can flourish.
Its a very low capex business , Even u can start -
The economics of these business are very similar to Airline business.
Equipments (Airplanes) are available on rent take it , start it, if works out good, if not return it 
There are other reasons also like - ( go through thread for the argument loosely put that big will keep becoming bigger)
For Eg - all 5 major players are in Delhi still revenue of Lal Chandani lab is growing. 5 Major players should have eaten it away by now if lal chandani lab don’t have any competitive advantage.
Reason is simple when 36 yrs ago they open this lab they built the trust of doctors, hospitals (B2B business) and customers overtime.
Yes, its challenging to expand - it will be very hard to become very big but lets see if this guy able to pull it off. he has scaled it up post IPO by opening 2 more labs, 10-15 collection centres and B2B contract with small hospitals.
On valuations even the current business can grow 7 % CAGR post Fy22 i.e, u are buying it still cheap on Fy22 earnings (which i think going to double).